is there any practical difference between using parenthesis for a single variable declaration (my($var);) and omitting them (my $var;)?
I can't test if there's any benchmark performance difference or if Perl::Critic has something to say about either styles, parenthesis impose list context in this scenario, and a list can be made of one or more elements.
This Post is in line and discusses a similar matter. The assignment to a scalar variable of a return value from a function (i.e such as stat()) or from an array gives the variable a value depending on the context in which the variable has been assigned, quoting an example below:
my ($var) = @array ;
my $var = @array;
Excellence is an Endeavor of Persistence.
A Year-Old Monk :D .